Heat Transfer and Mass Transfer from the Sphere at Low Reynolds Numbers

Abstract

Expressions for steady state rates of heat transfer and of mass transfer from a sphere immersed in a parallel flow of fluid consisting of two non.reacting component chemical species are derived. The Reynolds number is much less than unity and free convection is absent. Also, changes in sphere radius are neglected. Heat transfer due to thermal conduction and mass diffusion and mass transfer due to thermal diffusion, as well as transfer by convection, are taken into account. After linearizing the flow equations by supposing changes in flow quantities to be small compared to the flow quantities them· selves expressions for generalized Nusselt and Sherwood numbers are derived.. These expressions show clearly the interactions between the transfer processes, and, in the case of pure heat transfer or pure mass transfer yield, expressions for the usual Nusselt nd Sherwood numbers for a sphere, these expressions having the correct value of unity when the Reynolds number is zero.